World Star Hip Hop just released a video (above) of a man being confronted by a judge he knew from middle school. The judge asks him what school he went to, and the range of emotions he shows when he recognizes her - defiant politeness, pleasant surprise, then deep regret - is pure sadness and is very instructive.

A very popular activity in "Rebel to Ruler" is a simple writing exercise: "What advice would you give your ten-year-old self?" Similar exercises are direct routes to a kind of self-awareness that is valuable and rare. Often, what passes for self examination today are quasi-scientific attempts at describing personality traits. The results are unfulfilling, because these traits are about tendencies and potentials. These other exercises focus on a different kind of self-knowledge: one that is based on personal history.

Nostalgia is thought of as bittersweet around the world for a reason. Try answering the following questions: "Describe your career to your 14-year-old self." "Tell your 12-year-old self a true adventure story from your life." "What was your favorite hobby when you were 10 years old? When was the last time you did that hobby?" "Who were your friends in high school (or college)? When was the last time you spent time with them?"

If these questions evoke more bitter than sweet, remember that regret is wisdom that comes too late. Follow the advice of the stoics and conduct regular life reviews, and you won't be like the criminal in the video: breaking down the instant you see an acquaintance from your past. Imagine if he had seen her before he committed the crime.